Phosphonothioates



United States Patent 3,208,903 PHOSPHONOTHIOATES John P. Chupp, Kirkwood, Peter E. Newallis, Crestwood, and Joseph W. Baker, Kirkwood, Mo., assignors to Monsanto Company, a corporation of Delaware N0 Drawing. Filed Apr. 13, 1961, Ser. No. 102,659 19 Claims. (Cl. 167--30) This invention relates to novel phosphonothioates and to methods of making same. In addition this invention relates to insecticidal compositions containing these novel phosphonothio ates as an active ingredient.

The phosphonothioates of this invention can be termed O-(haloalkyl) phosphonothioates and can be represented by the formula RO S NO:

wherein R is a halogen substituted alkyl radical containing from 2 to '6 carbon atoms, wherein R is a hydrocarbyl radical containing from 1 to 8 carbon atoms, and wherein n is an integer from 0 to 1.

As illustrative of hydrocarbyl radicals are phenyl, xylyl, tolyl, ethylphenyl, benzyl, phenethyl, cyclopentyl, cyclohexyl, cycloheptyl, methylcyclohexyl, dimethylcyclohexyl, cyclohexylmethyl, methyl, ethyl, propyl, 'butyl, amyl, hexyl, heptyl, octyl, etc., and the various isomeric aryl, alkaryl, aralkyl, cycloalkyl, cycloalkyl-alkyl, alkyl, etc., forms thereof containing up to 8 carbon atoms and which are free of olefinic and acetylenic unsaturation.

By halogen substituted alkyl radical is meant alkyl radicals containing from 2 to 6 carbon atoms, the halogen substitution of which being halogen having an atomic number in the range of 8 to 36 (i.e. fluorine, bromine or chlorine, but particularly chlorine). Usually the halogen substituents will not exceed a total of 3 and can be like or unlike. These radicals are further characterized in that the alpha-carbon thereof is free of any halogen substitution and contains 1 (i.e. secondary carbon) or 2 (i.e. primary carbon) hydrogen substituents. As illustrative of such radicals are 2-chloroethyl, 2-bro moethyl, Z-fiuoroethyl, 2,2-dichloroethyl, 2,2-difiuoroethyl, 2-chloropropyl, 2,3-dichloropropyl, 3,3-dichloropropyl, 2,3-dibromopropyl, 1-chlorobutyl-2, l-ehlorobutyl-3, l-bromopropyl-Z, 3-bromo-1-chloropropyl-2, 4-chlorobutyl-2, 3,4-dichlorobutyl, 3,4-dibromobutyl, 4,5- dichloroamyl, 4-chlorohexyl, 4-chloroheXyl-3, 2,3,3-trichlorobutyl, 2,2,3-trichlorobutyl, etc.

A particularly useful class of phosphonothioates of this invention are those of the formula (CH H wherein m is whole number from 1 to 2 and wherein R is a chlorine substituted primary alkyl radical containing from 2 to 4 carbon atoms and containing from 1 to 2 chlorine substituents.

The method of this invention comprises reacting a nitrophenol of the formula nnH wherein n has the aforedescribed significance with a phosphonohalidothionate of the formula p-cresol, Z-nitro-o-cresol, etc. Usually the nitrophenol reactant will be 4-nitrophenol.

As illustrative of the phosphonohalidothionate reactants of the method of this invention are O-( Z-chloroethyl) methylphosphonochloridothionate,

O-(2-ch1oroethy1) ethylphosphonochloridothionate,

O-(2,2-dichloroethyl) ethylphosphonochloridothionate,

O-(2-chloroethyl) cyclohexylphosphonochloridothionate,

O-(Z-chloroethyl) benzylphosphonobromidothionate,

O-(Z-chloroethyl) phenylphosphonochloridothionate,

O-(2-chloroethyl) isobutylphosphonochloridothionate,

O-(3-chloropropyl) ethylphosphonochloridothionate,

O- (2-chloroethyl) n-propylphosphonochloridothionate,

O-(2,3-dichloropropyl) methylphosphonochloridothionate,

O(3,4-dichlorobutyl) ethylphosphonochloridothionate,

O-(3,3-dichloropropyl) n-butylphosphonobromidothionate,

O (4-chlorobutyl) ethylphosphonochloridothionate,

O-(2,3,3-trichloropropyl) n-propylphosphonochlo1idothionate,

O-(Z-bromoethyl) ethylphosphonochloridothionate,

O-(4-chlorobutyl-2) methylphosphonochloridothionate,

O-(3-bromo-l-chloropropyl-2) ethylphosphonochloridothionate,

O-(2,2-dichloroethyl) methylphosphonochloridothionate,

etc.

As illustrative of hydrogen halide scavenging agents of the method of this invention are sodium carbonate, potassium carbonate, the tertiary organic amines such as triethylamine, tripropylamine, tributylamine, dimethylaniline, lutidine, pyridine, 1-pipecoline, etc. These scavening agents will be employed ordinarily in an amount at lease sufiicient to absorb the hydrogen halide by-product of the reaction. They can be added at the beginning of the reaction or throughout the course of the reaction. Where and when desired an inert organic solvent such as benzene, toluene, Xylene, acetone, butanone, dioxane, etc., can be used.

While a wide range of reaction temperatures can be employed provided the system is fluid (i.e. a reaction 3 temperature above the freezing point of the system up to and including the boiling point of the system) it is preferred to employ a reaction temperature in the range of from about 10 C. to about 120 C. In general the nitrophenol reactant and the phosphonohalidothionate reactant will be employed in substantially equimolecular amounts.

As illustrative of the preparation of the phosphonothioates of this invention but not limitative thereof is the following:

EXAMPLE I To a suitable reaction vessel equipped with a thermometer, agitator and reflux condenser is charged approximately 80 parts by weight of benzene, approximately 6.9 parts by weight (substantially 0.05 mole) of 4- nitrophenol, approximately 6.1 parts by weight (substantially 0.06 mole) of triethylamine, and approximately 11.4 parts by weight (substantially 0.05 mole) of O-(2,2- dichloroethyl) methylphosphonochloridothionate. While agitating the mixture is heated up to the reflux temperature and then refluxed for 5 hours. The reaction mass is then cooled to room temperature and then quenched with water. The organic layer is separated and washed first with aqueous 3% sodium carbonate and then with water, The so-washed solution is then stripped of volatiles under vacuum. The residue, a solid (recrystallizing from hexane gave a M.P. of 59-60 C.) is O-(2,2-dichloroethyl) O-(4-nitrophenyl) methylphosphonothioate.

Analysis.--Theory: 9.4% P, 9.7% S, 21.5% C1. Found: 9.1% P, 9.7% S, 22.1% C1.

EXAMPLE II Employing the procedure of Example I but replacing 4-nitrophenol with an equimolecular amount of 2-nitrophenol there is obtained O-(2,2-dichloroethyl) O-(2- nitrophenyl) methylphosphonothioate which is insoluble in water.

EXAMPLE III To a suitable reactionvessel equipped with a thermometer, agitator and reflux condenser is charged approximately 80 parts by weight of benzene, approximately 5.98 parts by weight (substantially 0.043 mole) of 4-nitrophenol,approximately 4.34 parts by weight (substantially 0.043 mole) of triethylamine, and approximately 8.85 parts by weight (substantially 0.04 mole) of O-(4-chlorobutyl) methylphosphonochloridothionate. While agitating the mixture is heated' up to the reflux temperature and then refluxed for 5 hours. The reaction mass is then cooled to room temperature and then quenched with water. The organic layer is separated and washed first with aqueous 3% sodium carbonate and then with water. The so-washed solution is then stripped of volatile under vacuum. The residue is O-(4-chlorobutyl) O-(4-nitrophenyl) methylphosphonothioate.

Analysis-Theory: 9.6% P, 9.92% S, 11.0% C1. Found: 9.3% P, 9.8% S, 11.4% C1.

EXAMPLE IV Employing the procedure of Example III but replacing O (4 chlorobutyl) methylphosphonochloridothionate with an equimolecular amount of O-(4-chlorobutyl) ethylphosphonobromidothionate there is obtained O-(4- chlorobutyl) O-(4-nitrophenyl) ethylphosphonothioate which is insoluble in water.

EXAMPLE V To a suitable reaction vessel equipped with a thermometer, agitator and reflux condenser is charged approximately 80 parts by weight of benzene, approximate- 1y 7.36 parts by weight (substantially 0.053 mole) of 4- nitrophenol, approximately 5.35 parts by weight (substantially 0.053 mole) of triethylamine, and approximate- 1y 10.3 parts by weight (substantially 0.05 mole) of O (3 chloropropyl) methylphosphonochloridothionate.

4 While agitating the mixture is heated up to the reflux temperature and then refluxed for 5 hours. The reaction mass is then cooled to room temperature and then quenched with water. The organic layer is separated and washed first with aqueous 3% sodium carbonate and then with water. The so-washed solution is then stripped of volatiles under vacuum. The residue is 0-(3-chloropropyl) O-(4-nitrophenyl) methylphosphonothioate.

Analysis.Theory: 10% P, 10.3% S, 11.5% C1. Found: 9.7% P, 10.4% S, 12.1% C1.

EXAMPLE VI Employing the procedure of Example V but replacing 4-nitrophenol with an equimolecular amount of 3-methyl- 4-nitrophenol there is obtained O-(S-chloropropyl) O-(3- methyl-4-nitrophenyl) methylphosphonothioate which is insoluble in water.

EXAMPLE VII To a suitable reaction vessel equipped with a thermometer, agitator and reflux condenser is charged approximately parts by weight of benzene, approximately 7.36 parts by weight (substantially 0.53 mole) of 4-nitrophenol, approximately 5.35 parts by weight (substantially 0.053 mole) of triethylamine, and approximately 11.85 parts by weight (substantially 0.05 mole) of O-(2-bromoethyl) methylphosphonochloridothionate. While agitating the mixture is heated up to the reflux temperature and then refluxed for 5 hours. The reaction mass is then cooled to room temperature and then quenched with water; The organic layer is separated and washed first with aqueous 3% sodium carbonate and then with water. The so-washed solution is then stripped of volatiles under vacuum. The residue, an oil, is O-(Z-bromoethyl) O-(4- nitrophenyl) methylphosphonothioate.

Analysis.Theory: 9.1% P, 9.4% Found: 9.0% P, 9.8% S, 23.1% Br.

EXAMPLE VIII Employing the procedure of Example VII but replacing O (2 bromoethyl) methylphosphonochloridothionate with an equimolecular amount of O-(2,2-dibromoethyl) ethylphosphonochloridothionate there is obtained O-(2,2- dibromethyl) O-(4-nitrophenyl) ethylphosphonothioate which is insoluble in water.

EXAMPLE IX To a suitable reaction vessel equipped with a thermometer, agitator and reflux condenser is charged approximately parts by weight of benzene, approximately 6.95 parts by weight (substantially 0.05 mole) of 4-nitrophenol, approximately 6.1 parts by weight (substantially 0.06 mole). of triethylamine, and approximately 12.1 parts by weight (substantially 0.05 mole) of O- (2-bromoethyl) ethylphosphonochloridothionate. Whilev agitating the mixture is heated up to the reflux temperature and then refluxed for 4 hours. The reaction mass is then cooled to room temperature and then quenched with water. The organic layer is separated and washed first with aqueous 3% sodium carbonate and then with Water. The so-washed solution is then stripped of volatiles under vacuum. The residue, an oil, is 0-(2-bromoethyl) O-(4- nitrophenyl) ethylphosphonothioate.

Analysis.Theory: 8.65% P, 9.05% S, 3.95% N. Found: 8.7% P, 9.3% S, 4.1% N.

EXAMPLE" X Employing the procedure of Example IX but replacing 4-nitrophenol with an equimolecular amount of 2-nitro-. methylphenol there is obtained O-(2-bromoethyl) O-(2- nitro-4-methylphenyl) ethylphosphonothioate which is insoluble in water.

S, 23.5% Br.

EXAMPLE XI To a suitable reaction vessel equipped with a thermometer, agitator and reflux condenser is charged approxis mately 80 parts by weight of benzene, approximately 4.6 parts by Weight (substantially 0.033 mole) of 4-nitrophenol, approximately 4.1 parts by Weight (substantially 0.04 mole mole) of triethylamine, and approximately 6.6 parts by weight (substantially 0.03 mole) of O-(2-chloroethyl) n-propylphosphonochloridothionate. While agitaing the mixture is heated up to the reflux temperature and then refluxed for 6 hours. The reaction mass is then cooled to room temperature and then quenched with water. The organic layer is separated and washed first with aqueous 3% sodium carbonate and then with water. The so-Washed solution is then stripped of volatiles under vacuum. The residue, (recrystallizing from hexane gave a MP. of 42-42.5 C.) is O-(2-chloroethyl) O-(4-nitrophenyl) n-propylphosphonothioate.

Analysis-Theory: 9.9% S, 4.3% N. Found: 10.1% S, 4.3% N.

EXAMPLE XII Employing the procedure of Example XI but replacing O (2 chloroethyl) n propylphosphonochloridothionate with an equimolecular amount of O-(2,2-dichloroethyl) cyclohexylphosphonobromidothionate there is obtained (2,2-dichloroethyl 0-(4-nitrophenyl) cyclohexylphosphonothioate which is insoluble in water.

EXAMPLE XIII To a suitable reaction vessel equipped with a thermometer, agitator and reflux condenser is charged approximately 80 parts by weight of benzene, approximately 6.94 parts by weight (substantially 0.053 mole) of 4- nitrophenol, approximately 5.25 parts by weight (substantially 0.052 mole) of triethylamine, and approximately 12.5 parts by weight (substantially 0.05 mole) of O-(3- bromopropyl) methylphosphonochloridothionate. While agitating the mixture is heated up to the reflux temperature and then refluxed for 4 hours. The reaction mass is then cooled to room temperature and then quenched with water. The organic layer is separated and washed first with aqueous 3% sodium carbonate and then with water. The so-washed solution is then stripped of volatiles under vacuum. The residue, an oil, is O-(3-bromopropyl) O- (4-nitrophenyl) methylphosphonothioate.

Analysis-Theory: 9.2% P, 9.5% S. Found: 8.5% P, 10.0% S.

EXAMPLE XIV Employing the procedure of Example XIII but replacing O-(3-bromopropyl) methylphosphonochloridothionate with an equimolecular amount of O-(3,3-dibromopropyl) benzylphosphonochloridothionate there is obtained O-(3, 3-dibromopropyl) O-(4-nitrophenyl) benzylphosphonothioate which is insoluble in water.

EXAMPLE XV To a suitable reaction vessel equipped With a thermometer, agitator and reflux condenser is charged approximately 80 parts by weight of benzene, approximately 8.3 parts by weight (substantially 0.06 mole) of 4-nitrophenol, approximately 6.25 parts by weight (substantially 0.062 mole) of triethylamine, and approximately 11.6 parts by weight (substantially 0.06 mole) of O-(Z-chloroethyl) methylphosphonochloridothionate. While agitating the mixture is heated up to the reflux temperature and then refluxed for 5 hours. The reaction mass is then cooled to room temperature and then quenched with water. The organic layer is separated and washed first with aqueous 3% sodium carbonate and then with water. The sowashed solution is then stripped of volatiles under vacuum. The residue, an oil, is O-(Z-chloroethyl) O-(4-nitrophenyl) methylphosphonothioate.

AnaZysis.TheOry: 10.5% P, 10.8% S, 12.0% C1. Found: 10.3% P, 11.0% S, 11.78% Cl.

6 EXAMPLE XVI Employing the procedure of Example XV but replacing 4-nitrophenol with an equimolecular amount of 3-methyl- 4-nitrophenol there is obtained O-(2-chloroethyl) O-(3- methyl-4-nitrophenyl) methylphosphonothioate which is insoluble in water.

EXAMPLE XVII To a suitable reaction vessel equipped with a thermometer, agitator and reflux condenser is charged approximately 125 parts by weight of benzene, approximately 8.3 parts by Weight (substantially 0.06 mole) of 4-nitrophenol, approximately 6.6 parts by weight (substantially 0.065 mole) of triethylamine, and approximately 12.4 parts by Weight (substantially 0.06 mole) of O-(2-chloroethyl) ethylphosphonochloridothionate. While agitating the mixture is heated up to the reflux temperature and then refluxed for 6 hours. The reaction mass is then cooled to room temperature and then quenched with water. The organic layer is separated and washed first with aqueous 3% sodium carbonate and then with water. The sowashed solution is then stripped of volatiles under vacuum. The residue, an oil, is O-(2-chloroethyl) O-(4- nitrophenyl) ethylphosphonothioate.

Analysis.Theory: 10.0% P, 11.5% CI, 4.5% N. Found: 9.9% P, 11.4% C1, 4.4% N.

EXAMPLE XVIII Employing the procedure of Example XVII but replacing O-(2-chloroethyl) ethylphosphonochloridothionate with an equimolecular amount of O-(2,2-dichloroethyl) n-octylphosphonochloridothionate there is obtained O-(2, 2-dichloroethyl) O-(4-nitrophenyl) n-octylphosphonothioate which is insoluble in water.

EXAMPLE XIX To a suitable reaction vessel equipped with a thermometer, agitator and reflux condenser is charged approximately 200 parts by weight of benzene, approximately 6.95 parts by weight (substantially 0.05 mole) of 4-nitrophenol, approximately 6.1 parts by Weight (substantially 0.06 mole) of triethylamine, and approximately 11.0 parts by weight (substantially 0.05 mole) of O-(3-chloropropyl) ethylphosphonochloridothionate. While agitating the mixture is heated up to the reflux temperature and then refluxed for 5 hours. The reaction mass is then cooled to room temperature and then quenched with Water. The organic layer is separated and washed first with aqueous 3% sodium carbonate and then with water. The so-washed solution is then stripped of volatiles under vacuum. The residue, an oil, is O-(3 -chloropropyl) O- (4-nitrophenyl) ethylphosphonothioate.

Analysis-Theory: 9.6% P, 9.9% S, 4.3% N, 11.0% C1. Found: 9.2% P, 10.2% S, 4.3% N, 11.3% C1.

EXAMPLE XX Employing the procedure of Example XIX but re placing O-(3-chloropropyl) ethylphosphonochloridothiomate with an equimolecular amount of O-(4,4-dichlorobutyl) methylphosphonochloridothionate there is obtained O-(4,4-dichlorobutyl) O- (4-nitrophenyl) methylphosphonothioate which is insoluble in water.

EXAMPLE XXI To a suitable reaction vessel equipped with a thermom eter, agitator and reflux condenser is charged approximately parts by weight of benzene, approximately 5.56 parts by weight (substantially 0.04 mole) of 4- nitrophenol, approximately 5.1 parts by Weight (substantially 0.05 mole) of triethylamine, and approximately 8.65 parts by weight (substantially 0.04 mole) of O-(6- chlorohexyl) methylphosphonochloridothionate. While agitating the mixture is heated up to the reflux tempera ture and then refluxed for 5 hours. The reaction mass is then cooled to room temperature and then quenched EXAMPLE XXII Employing the procedure of Example XXI but replacing -(6-chlorohexyl) methylphosphonochloridothionate with an equimolecular amount of O-(6,6,6-trichlorohexyl) methylphosphonochloridothionate there is obtained O-(6,6,6-trichlorohexyl) O-(4-nitrophenyl) methylphosphonothioate which is insoluble in water.

EXAMPLE XXIH To a suitable reaction vessel equipped with a thermom-v eter, agitator and reflux condenser is charged approximately 80 parts by weight of benzene, approximately 7.36 parts by weight (substantially 0.053 mole) of 4-nitrophenol, approximately 5.35 parts by weight (substantially 0.053 mole). of triethylamine, and approximately 12.1 parts by weight (substantially 0.05 mole) of O-(2,3- dichloropropyl) methylphosphonochloridothionate. While agitating the mixture is heated up to the reflux temperature and then refluxed for hours. The reaction mass is then cooled to room temperature and then quenched with water. The organic layer is separated and washed first with aqueous 3% sodium carbonate and then with water. The so-washed solution is then stripped of volatiles under vacuum. The residue, an oil, is O-(2,3-dichloropropyl) O-(4 nitrophenyl) methylphosphonothioate.

Analysis.Theory: 9.0% P, 9.3% S, 20.6% C1. Found: 8.9% P, 9.5% S, 20.9% C1.

EXAMPLE XXIV Employing the procedure of Example XXIII but replacing 4-nitrophenol with an equimolecular amount of 3-nitro-4-methylphenol there is obtained O-(2,3dichloropropyl) O-(3-nitro 4 methylphenyl) methylphosphonothioate which is water-insoluble.

EXAMPLE XXV To a suitable reaction vessel equipped with a thermometer, agitator and reflux condenser is charged approximately 80 parts by weight of benzene, approximately 6.1 parts by weight (substantially 0.044 mole) of 4-nitrophenol, approximately 5.1 parts by weight (substantially 0.05 mole) of triethylamine, and approximately 9.4 parts by weight (substantially 0.04 mole) of O-(2-chlo'rocthyl) n-butylphosphonochloridothionate. While agitating the mixture is heated up to the reflux temperature and then refluxed for 5 hours. The reaction mass is then cooled to room temperature and then quenched with Water. The organic layer is separated and washedfirst with aqueous 3% sodium carbonate and then with water. The so-washed solution is then stripped of volatiles under vacuum. The residue (recrystallizing from hexane gave a M.P. of 40-41 C.) is O-(Z-chloroethyl) O-(4-nitropheuyl) n-butylphosphonothioate.

Analysis-Theory: 9.26% P, 9.45% S, 10.5% C1. Found: 9.1% P, 9.6% S, 10.4% Cl.

v EXAMPLE XXVI Employing the procedure of Example XXV but replacing O-(Z-chloroethyl) n-butylphosphonochloridothionate with an equimolecular amount of O-'(2-.2-dichloroethyl) 2-ethylphenylphosphonobromidothionate there is obtained O-(2,2-dichloroethyl) O-(4-nitrophenyl) Z-ethylphenylphosphonothioate which is insoluble in water.

EXAMPLE XXVII To a suitable reaction vessel equipped with a thermometer, agitator and reflux condenser is charged approxiwashed first with aqueous 3% 8 mately 160 parts by weight of benzene, approximately 695 parts by Weight (substantially 0.05 mole) of 4- nitrophenol, approximately 6.1 parts by weight (substantially 0.06 mole) of triethylamine, and approximately 10.6 parts by weight (substantially 0.05 mole) of O- (2,2,2-trifluoroethyl) methylphosphonochloridothionate. While agitating the mixture is heated up to the reflux temperature and thenrefluxed for 5 hours. The reaction mass is then cooledto room temperature and then quenched with water. The organic layer is separated and Washed first with aqueous 3%sodium carbonate and then with water. The so-washed solution is then stripped of volatiles under vacuum. The residue, a solid, is O-(2,2,2-tnifluoroethyl) Q-(4-nitrophenyl) methylphosphonothioiate (M.P. 35-36 C.).

Analysis.-Theory: 9.8% P, 10.1% Found: 9.7% P, 10.1 S, 4.59% N.

EXAMPLE XXVIII EXAMPLE XXIX To a suitable reaction vessel equipped with a thermometer, agitator and reflux condenser is charged approximately 150 parts by weight of benzene, approximately 6.95 parts by weight of 4-nitropheno l, approximately 6.1 parts by weight of triethylamine, and approximately 12 parts by weight of 'O-(2,2,2-trichloroethyl) methylphosphonochloridothionate. While agitating the mixture is heated up to the reflux temperature and then refluxed for 5 hours. The reaction mass is then cooled to room temperature and then quenched with water. The organic layer is separated and washed first with aqueous 3% sodium carbonate and then with water. The s o-washed solution is then stripped of volatiles under vacuum. The 'residue, (recrystallizing from hexane gave a M.P. of

7778 C.) is O-(2,2,2-trichloroethyl) O-(4-nitrophenyl) To a suitable reaction vessel equipped with a thermometer, agitator and reflux condenser is charged approximately 80 parts by weight of benzene, approximately 6.9 parts by weight (substantially 0.05 mole) of 4-nitrophenol, approximately 5.1 parts by weight (substantially 0.05 mole) of triethylamine, and approximately 13.8 parts by weight (substantially 0.057 mole) of O-(l,3- dichloropropyl 2) methylphosphonochloridothionate. While agitating the mixture isheated up to the reflux temperature and then refluxed for 5 hours. The reaction mass is then cooled to room temperature. and then quenched with water. The organic layer is separated and sodium carbonate and then with water. The so-washed solution is then stripped of volatiles under vacuum. The residue, a solid, is

O-(l,3-dichloropropyl-2) O-(4-nitrophenyl) methylphosphonothioate.

Analysis.-Theory: 9.02% P, 9.3% P, 9.8% S.

S. Found: 9.1%

EXAMPLE XXXI To. a suitable reaction vessel equipped with a thermometer, agitator and reflux condenser is charged approxi- .mately 80 parts by weight of benzene, approximately 7.36

parts by Weight (substantially 0.053 mole) of 4-nitrophenol, approximately 5.35 parts by weight (substantially EXAMPLE XXXII To a suitable reaction vessel equipped with a thermometer, agitator and reflux condenser is charged approximately 80 parts by weight of benzene, approximately 5.5 parts by weight (substantially 0.04 mole) of 4-nitrophenol, approximately 5.1 parts by weight (substantially 0.05 mole) of triethylamine, and approximately 8.0 parts by weight (substantially 0.036 mole) of O-(2-chloroethyl) isopropylphosphonochloridothionate. While agitating the mixture is heated up to the reflux temperature and then refluxed for 6 hours. The reaction mass is then cooled to room temperature and then quenched with water. The organic layer is separated and washed first with aqueous 3% sodium carbonate and then with water. The so washed solution is then stripped of volatiles under vacuum. The residue, (recrystallizing from hexane gave a MP. of 50-51 C.) is O-(2-chloroethyl) O-(4-nitrophenyl) isopropylphosphonothioate.

Analysis.Theory: 9.6% P, 9.9% S, Found: 9.5% P, 10.2% S, 11.1% N.

EXAMPLE XXXIII To a suitable reaction vessel equipped with a thermometer, agitator and reflux condenser is charged approximately 80 parts by weight of benzene, approximately 6.1 parts by weight of 4-nitrophenol, approximately 5.1 parts by weight of triethylamine, and approximately 9.6 parts by weight of O-(3,3-dichloropropyl) methylphosphonochloridothionate. While agitating the mixture is heated up to the reflux temperature and then refluxed for 6 hours. The reaction mass is then cooled to room temperature and then quenched with water. The organic layer is separated and washed first with aqueous 3% sodium carbonate and then with Water. The so-washed solution is then stripped of volatiles under vacuum. The residue, a solid, is O-(3,3-dichloropropyl) O- 4-nitrophenyl) methylphosphonothioate (M.P. 69-715 C.).

Analysis.-Theory: 9.0% P, 9.3% Found: 8.9% P, 9.5% S, 20.8% C1.

' The methods by which the phosphonothioates of this Additionally an inert organic solvent can be added to and in the purification by absorptive agent. I-lowever, the product is generally satisfactory for insecticidal purposes without further purification.

As illustrative of other phosphonothioates of this invention are O-(2,3-dichloro-n-hexyl) O-(4-nitrophenyl) methylphosphonothioate O-(2-chloroethyl) O-(3-nitrophenyl) methylphosphonothioate O-(Z-chloropropyl) O-(4-nitrophenyl) ethylphosphonothioate O-(3,3-dichloropropyl) O-(4-nitropheny1) n-propylphosphonothioate O-(4-chlorobutyl) O-(4-nitropheny1) phenylphosphonothioate O-(3chlor0butyl) O-(4-nitrophenyl) phenylphosphonothioate O-(2-chloroethyl) O-(4-nitrophenyl) 2-(phenyl) ethylphosphonothioate It will be understood that the terms insect and insecticide unless otherwise modified are used herein in their broad common usage to include spiders, mites, ticks and like pests which are not in the strict biological sense classed as insects. Thus, the usage herein conforms to the definitions provided by Congress in Public Law 104, the Federal Insecticide, Fungicide, and Rodenticide Act of 1947, Section 2, subsection h, wherein the term insect is used to refer not only to those small invertebrate animals belonging mostly to the class Insecta, comprising six-legged usually winged forms, as beetles, bugs, bees, flies, and so forth, but also to other allied classes or arthropods whose members are Wingless and usually have more than six legs, as spiders, mites, ticks, centipedes, and wood lice.

The phosphonothioates of this invention are effective against a wide variety of insect pests. As illustrative of the activity but not limitative thereof is the following:

A rimless, 25 x 200 mm. culture tube is rinsed with acetone and is placed in a holding block. The tube is filled with 50 cc. of distilled water. Next 0.1 cc. or 0.1 gram of the compound to be evaluated is dissolved in acetone .to make a 1% by weight concentrate of the compound. 0.05 ml. of this concentrate is pipetted into the culture tube containing the distilled water. The tube is then stoppered with an acetone washed rubber stopper and shaken vigorously to facilitate complete mixing. Approximately 25 early fourth instar yellow fever mosquito larvae (Aedes aegypti) are transferred to the tube with the aid of a pipette. The larvae are held in the test tube at room temperature for 24 hours at which time mortality observations are taken. This procedure is repeated at decreasing concentrations until a kill is observed. Employing the below itemized compounds 100% kills were observed at the indicated concentrations in parts per million:

P.p.m. O-(2,2-dichloroethyl) O-(4-nitrophenyl methylphosphonothioate 0.04 O-(4-chlorobutyl) O-(4-nitrophenyl) methylphosphonothioate 0.004 O-(3 -chloropropyl) O-(4-nitrophenyl) methylphosphonothioate 0.004 O-(2-bromoethyl) O-(4-nitrophenyl) methylphosphonothioate 0.016 O-(Z-bromoethyl) O-(4-nitrophenyl) ethylphosphonothioate 0.04 O-(Z-chloroethyl) O-(4-nitrophenyl) n-propylphosphonothioate 0.04 O-(3 -bromopropyl) O-(4-nitrophenyl) methylphosphonothioate 0.04 O-(2-chloroethyl) O-(4-nitrophenyl) methylphosphonothioate 0.004 O-(Z-chloroethyl) O-(4-nitr0phenyl) ethylphosphonothioate 0.008 O- (3 -chloropropyl) O- (4-nitrophenyl) ethylphosphonothioate 0.04 O-(6-chlorohexyl) O-(4-nitrophenyl) methylphosphonothioate 0.4

O-(2,3-dichloropropyl) O-(4-nitrophenyl) methyl- '11 r P.p.m. phosphonothioate 0.016 O-(2-chloioethyl) O-(4-nitrophenyl) n-butylphosphonothioate 0.4 O-(2,2,2-trifluoroethyl) O-(4-nitrophenyl) methylphosphonothioate 0.4 O-(2,2,2-trichloroethyl) O-(4-nitrophenyl) methylphosphonothioate 0.06 O-(1,3-dichloropropyl-2) O-(4-nitrophenyl) methylphosphonothioate 0.06 O-(2-chloroethyl) O-(4-nitrophenyl) phenylphosphonothioate 0.06

A 1% by weight concentrate is prepared by dissolving the compound to be evaluated in 10 ml. of acetone. A 0.25 cc. tuberculin, D-B Yale syringe is filled with this concentrate and placed in a microinjection apparatus. The injector lever is pressed several times to make certain no air bubbles are trapped in the needle and the needle is wiped with filter paper to remove any excess solution. The injector lever is pressed once .to deliver one microliter which is applied directly to each of 12 lima bean leaf discs 0.25 inch in diameter. Individual second instar southern armyworm larvae (Prodenia eridania) are placed on each diseand the disc encaged with a plastic cap. After 48 hours at room temperature mortality observations are made. This procedure is repeated at decreasing concentrations and until a 100% kill is observed. Employing the below itemized compounds 100% kills were observed at the indicated concentrations in micrograms per larva:

O-(2,2-dichloroethyl) O (4 nitrophenyl) methyl- O-(2,2,2-trichloroethyl) O-(4-nitrophenyl) methylphosphonothioate 6 O-(1,3-,dichloropropyl-2) O-(4-n'itrophenyl) methylphosphonothioate 0.63

O-(Z-chloroethyl) O (4 nitrophenyl) phenylphosphonothioate 0 63 A 1% weight concentrate of the compound to be evaluated is prepared by dissolving the chemical in ml. of acetone. A 0.25 cc. tuberculin, B-D Yale syringe is filled with the concentrate and placed in a microinjection apparatus. The injector lever is pressed several times to make certain that no air bubbles are trapped in the needle and the needle is wiped with filter paper to remove any excess solution. The injector lever is pressed once to produce one microliter which is applied directly to the ventral side of the abdomen of each of 10 plum curculio (Conotrachelus nenuphar) After application each insect is released within o bservation dishes and held for 24 hours at room temperature and mortality observations made at the end of that time. This procedure is repeated at decreasing concentrations until a 100% kill is observed. Employing the below itemized compounds 100% kills were observed at the indicated concentration in micrograms per insect:

12 O- (2,2-dichloroethyl) O-(4-nitrophenyl) methylphosphonothioate 0.20 O-(4-chlorobutyl) O-(4-nitrophenyl) methylphosphonothioate 0.16 'O-(3-chloropropyl) O (4 nitrophenyl) methylphosphonothioate 0.04 O-(2-bromoethyl) O-(4-nitrophenyl) 'methylphosphonothioate 0.16 O-(2-bromoethyl) O (4-nitrophenyl) ethylphosphonothioate 0.20 O-(2-chl-oroethyl) O (4 nitrophenyl) n-propylphosphonothioate 0.20 'O-(3-bromopropyl) O (4 nitrophenyl) methyl phosphonothioate 0.20 O-(2-chloroethyl) O- (4-nitrophenyl) ethylphosphonothioate 0.054 O-(3chl oropropyl) O-(4-nitrophenyl) ethylphosphonothioate 0.02 'O-(6-chlorohexyl) O-(4-nitrophenyl) methylphosphonothioate 2.00 O-(2,3-dichloropropyl) O-(4-nitrophenyl) methylpho-sphonothioate 0.63

Although the phosphonothioates of this invention are useful per se in controlling a wide variety of insect pests, it is preferable that they be supplied to the pests or to the environment of the pest 'or pests in a dispersed form in a suitable extending agent.

In the instant specification and appended claims it is to be understood that the term dispersed is used in its widest possible sense. When it is said that the phosphonothioates of this invention are dispersed, it means that particles of the phosphonothioates of this invention may be molecular in size and held in true solution in a suitable organic solvent. It means further, that the particles may be colloidal in size and distributed throughout .a liquid phase in the form of suspensions or emulsions or -in the form of particles held in suspension by wetting agents. It also includes particles which are distributed in a semi-solid viscous carrier such as petrolatum or soap or other ointment base in which they may be actually dissolved in the semi-solid or held in suspension in the semi-solid with the aid of suitable wetting or emulsifying agents. The term .dispersed also means that the particles may be mixed with and distributed throughout a solid carrier providing a mixture in particulate form, e.g. pellets, granules, powder-s, or dusts. The term dispersed also includes mixtures which are suitable for use as aerosols including solutions, suspensions, or emulsions of the phosphonothioates of this invention in a carrier such as dichlorodifluoromethane and the like fluorochloroalkanes which boil below room temperature at atmospheric pressure.

In the instant specification and appended claims it is to be understood that the expression extending agent includes any and all of those substances in which the phosphonothioates of this invention are dispersed. It includes, therefore, the solvents of a true solution, the liquid phase of suspensions-emulsions or aerosols, the semi-solid carrier of ointments and the solid phase of particulate solids, e.g. pellets, granules, dusts and powders.

The exact concentration of the phosphonothioates of this invention employed in combatting or controlling insect pests can vary considerably provided the required dosage (i.e. toxic or lethal amount) thereof is supplied to the pests or to the environment of the pests. When the extending agent is a liquid or mixture of liquids (e.g. as in solutions, suspensions, emulsions, or aerosols) the concentration of the phosphonothioate employed to supply the desired dosage generally will be in the range of 0.001 to 50 percent by weight. When the extending agent is a semi-solid or solid, the concentration of the phosphonothioate employed to supply the desired dosage generally will be in the range of 0.1 to 25 percent by weight. From a practical point of view, the manufacturer must supply the agriculturist with a low-cost concentrate or spray base or particulate solid base in such form that, by merely mixing with water or solid extender (e.g. powdered clay or talc) or other low-cost material available to the agriculturist at the point of use, he will have an easily prepared insecticidal spray or particulate solid. In such a concentrate composition, the phosphonothioate generally will be present in a concentration of to 95 percent by weight, the residue being any one or more of the well known insecticidal adjuvants, such as the various surface active agents (e.g. detergents, a soap or other emulsifying or wetting agent), surface-active clays, solvents, diluents, carrier media, adhesives, spreading agents, humectants, and the like.

There are a large number of organic liquids which can be used for the preparation of solutions, suspensions or emulsions of the phosphonothioates of this invention. For example, isopropyl ether, acetone, methyl ethyl ketone, dioxane, cyclohexanone, carbon tetrachloride, ethylene dichloride, tetrachloroethane, hexane, heptane and like higher liquid alkanes, hydrogenated naphthalenes, solvent naphtha, benzene, toluene, xylene, petroleum fractions (e.g. those boiling almost entirely under 400 F. at atmospheric pressure and having a flash point above about 80 F., particularly kerosene), mineral oils having an unsulfonatable residue above about 80 percent and preferably above about 90 percent. In those instances wherein there may be concern about the phytotoxicity of the organic liquid extending agent a portion of same can be replaced by such low molecular weight aliphatic hydrocarbons as dipentene, diisobutylene, propylene trimer, and the like or suitable polar organic liquids such as the aliphatic ethers and the aliphatic ketones containing not more than about carbon atoms as exemplified by acetone, methyl ethyl ketone, diisobutyl ketone, dioxane, isopropyl ether, and the like. In certain instances, it is advantageous to employ a mixture of organic liquids as the extending agent.

When the phosphonothioates of this invention are to be supplied to the insect pests or to the environment of the pests as aerosols, it is convenient to dissolve them in a suitable solvent and disperse the resulting solution in dichloro-difiuoromethane or like chlorofluoroalkane which boils below room temperature at atmospheric pressure.

The phosphonothioates of this invention are preferably supplied to the insect pests or to the environment of the insect pests in the form of emulsions or suspensions. Emulsions or suspensions are prepared by dispersing the phosphonothioate of this invention either per se or in the form of an organic solution thereof in water with the aid of a water-soluble surfactant. The term surfactant as employed here and in the appended claims is used as in volume II of Schwartz, Perry and Berchs Surface Active Agents and Detergents (1958, Interscience Publishers, Inc., New York) in place of the expression emulsifying agent to connote generically the various emulsifying agents, dispersing agents, wetting agents and spreading agents that are adapted to be admixed with the active compounds of this invention in order to secure better wetting and spreading of the active ingredients in the water vehicle or carrier in which they are insoluble through lowering the surface tension of the water (see also Frear Chemistry of Insecticides, Fungicides and Herbicides, Second edition, page 280). These surfactants include the well-known capillary-active substances which may be anion-active (or anionic), cation active (or cationic), or non-ionizing (or non-ionic) which are described in detail in volume I and II of Schwartz, Perry and Berchs Surface Active Agents and Detergents (1958, Interscience Publishers, Inc., New York) and also in the November 1947 issue of Chemical Industries (pages 811-824) in an article entitled Synthetic Detergents by John W. Mc- Cutcheon and also in the July, August, September and October 1952 issues of Soap and Sanitary Chemicals under the title Synthetic Detergents. The disclosures of these articles with respect to surfactants, i.e. the anion-active, cation-active and the non-ionizing capillary active substances, are incorporated in this specification by reference in order to avoid unnecessary enlargement of this specification. The preferred surfactants are the water-soluble anionic surface-active agents and the water-soluble nonionic surface-active agents set forth in US. 2,846,398 (issued August 5, 1958). In general it is preferred that a mixture of water-soluble anionic and water-soluble nonionic surfactants be employed.

The phosphonothioates of this invention can be dispersed by suitable methods (e.g. tumbling or grinding) in solid extending agents either of organic or inorganic nature and supplied to the insect pests environment in particulate form. Such solid materials include for example, tricalcium phosphate, calcium carbonate, kaolin, bole, kieselguhr, talc, bentonite, fullers earth, pyrophillite, diatomaceous earth, calcined magnesia, volcanic ash, sulfur and the like inorganic solid materials, and include, for example, such materials of organic nature as powdered cork, powdered wood, and powdered walnut shells. The preferred solid carriers are the adsorbent clays, e.g. bentonite. These mixtures can be used for insecticidal pur poses in the dry form, or, by addition of water-soluble surfactants or wetting agents the dry particulate solids can be rendered wettable by water so as to obtain stable aqueous dispersions or suspensions suitable for use as sprays.

For special purposes the phosphonothioates of this invention can be dispersed in a semi-solid extending agent such as petrolatum or soap (e.g. sodium stearate or oleate or palmitate or mixtures thereof) with or Without the aid of solubility promoters and/or surfactants or dispersing agents.

In all of the forms described above the dispersions can be provided ready for use in combatting insect pests or they can be provided in a concentrated form suitable for mixing with or dispersing in other extending agents. As illustrative of a particularly useful concentrate is an intimate mixture of phosphonothioate of this invention with a water-soluble surfactant which lowers the surface tension of water in the weight proportions of 0.1 to 15 parts of surfactant with sufiicient of the phosphonothioate of this invention to make 100 parts by weight. Such a concentrate is particularly adapted to be made into a spray for combatting various forms of insect pests by the addition of water thereto. As illustrative of such a concentrate is an intimate mixture of parts by weight of O-(2,2-dichloroethyl) O-(4-nitrophenyl) methylphosphonothioate and 5 parts by weight of a water-soluble nonionic surfactant such as the polyoxyethylene derivative of sorbitan monolaurate.

Another useful concentrate adapted to be made into a spray for combatting a variety of insect pests is a solution (preferably as concentrated as possible) of a phosphonothioate of this invention in an organic solvent therefor. The said liquid concentrate preferably contains dissolved therein a minor amount (e.g. 0.5 to 10 percent by weight of the weight of the new insecticidal agent) of a surfactant (or emulsifying agent), which surfactant is also water-soluble. As illustrative of such a concentrate is a solution of O-(4-chlorobutyl) O-(4-nitrophenyl)methyl phosphonothioate in benzene which solution contains dissolved therein a water-soluble polyoxyethylene glycol non-ionic surfactant and a water-soluble alkylaryl sulfonate anionic surfactant.

Of the surfactants aforementioned in preparing the various emulsifiable, wettable, or dispersible compositions or concentrates of this invention, the anionic and nonionic surfactants are preferred. Of the anionic surfactants, the particularly preferred are the well known water-soluble alkali metal alkylaryl sulfonates as exemplified by sodium decylbenzene sulfonate and sodium dodecylbenzene sulfonate. Of the non-ionic surfactants, the particularly preferred are the water-soluble polyoxywherein R is primary alkyl containing atoms, and wherein R taining from 2 to 6 carbon atoms and from 1 to 3 chlorine ethylene derivative of alkylphenols (particularly isooctyl: phenol) and the water-soluble polyoxyethylene derivatives of the mono-higher fatty acid esters of hexitol anhydrides (e.g. sorbitan). These materials in general contain 15 to 30'moles of ethylene oxide per mole of the hexitol anhydride or the alkylphenol.

In all of the various dispersions described hereinbefore for insecticidal purposes, the active ingredient can be one or more of the compounds of this invention. The com-, pounds of this invention can also be advantageously employed in combination with other pesticides, including for example, nematocides, bactericides, and herbicides. In this manner it is possible to obtain mixtures which are effective against a wide variety of pests and other forms of noxious life.

In controlling or combatting insect pests the phosphonothioates of this invention either per se or compositions comprising same are supplied to the insect pests or to their environment in a lethal or toxic amount. This can be done by dispersing the new insecticidal agent or insecticidal composition comprising same in, on or over an infested environment or in, on or over an environment the insect pests frequent, e.g. agricultural soil or other growth media or other media infestedwith insect pests or attractable to the pests for habitational or sustenance or propagational purposes, in any conventional fashion which permits contact between the insect pests and the phosphonothioates of this invention. Such dispersing can be brought about by applying sprays or particulate solid'compositions to a surface infested with the insect pests or attractable to the pests, as for example, the surface of an agricultural soil or other media such as the above ground surface of plants by any of the conventional methods, e.g. power duster-s, boom and hand sprayers, and spray dusters. Also for sub-surface application such dispersing can be carried out by simply mixing the new insecticidal agent per se or insecticidal spray or particulate solid compositions comprising same with the infested environment or with the environment the insect pests frequent, or by employing a liquid carrier for the new insecticidal agent to accomplish'sub-surface penetration and impregnation therein.

While this invention has been described with respect to certain embodiments, it is to be understood that it is not so limited that variations and modifications thereof obvious to those skilled in the art can, be made without departing from the spirit and scope thereof.

What is claimed is:

1. A phosphonothioate of the formula wherein n is an integer from to 1, wherein R is hydrocarbon containing from 1 to 8 carbon atoms and is free of olefinic and acetylinic unsaturation, and wherein R is halogen substituted alkyl containing from 2 to 6 carbon atoms, the said halogen substitution being halogen having an atomic number in the range of 8 to 36, the alpha-carbon of said R being free of any halogen substitution and containing from 1 to 2hydrogen substituents.

2. An O- (nitrophenyl) phosphonothioate of the formula from 1 to 4 carbon is chlorine substituted alkyl consubstituents, the alpha-carbon of said R having two hydrogen substituents.

16 3. An O-(4-nitrophenyl) phosphonothioate of the formula wherein m is a whole number from 1 to 2, and wherein R is chlorine substituted alkyl containing from 2 to 4 carbon atoms and from 1 to 2 chlorine substituents, the alphacarbon of said R having two hydrogen substituents.

4. O (2,2-dichloroethyl) O- (4-nitrophenyl) methylphosphonothioate.

5. O (4-chlorobutyl) O-(4-nitrophenyl) methylphosphonothioate.

6. O (3-chloropropyl) O-(4-nitrophenyl) methylphosphonothioate.

7. O (2-chloroethyl) O-(4-nitrophenyl) methylphosphonothioate.

8. O (Z-chloroethyl) O-(4-nitrophenyl) ethylphosphonothioate.

9. The method which comprises reacting a nitrophenol of the structure wherein n is an integer from 0 to 1 with a phosphonohalidothionate of the structure wherein Z is a halogen of atomic number in the range of 16 to 36,. wherein R is hydrocarbon containing 1 to 8 carbon atoms and which is free of olefinic and acetylenic unsaturation, and wherein R is halogen substituted alkyl containing 2 to 6 carbon atoms, the said halogen substitution being halogen having an atomic number in the range of 8 to 36, the alpha-carbon of said R being free of any halogen substitution and containing 1 to 2 hydrogen substituents, in the presence of a hydrogen halide scavenging agent.

10. An insecticidal composition comprising a compound of claim 1 dispersed in an extending agent.

pound of claim 1 dispersed in a liquid extending agent,

the composition containing 0.001 to 50 percent by weight of said compound of claim 1.

13. An insecticidal concentrate comprising a compound of claim 1 and an-insecticidal adjuvant, said concentrate containing from 5 to percent by weight of the compound of claim 1.

14. An insecticidal concentrate comprising a compound of claim 1 dispersed in an organic solvent therefor andhaving dissolved therein a minor amount of a surfactant, said concentrate forming an emulsion with water upon agitation therewith.

15. An insecticidal concentrate adapted. to be made intoa sprayable composition by the addition of water comprising a compound of claim 1 in admixture with a water-soluble surfactant in the weight proportion of 0.1

to 15 parts of surfactant and sufiicient of said compound of claim 1 to make parts by weight.

1 7 1 8 16. The method of'controlling insects which comprises References Cited by the Examiner contacting the insects with a toxic amount of a compound UNITED STATES PATENTS of claim 1. 17. The method for protection of plants against insect gf g i attack which comprises applying to the plant an insecti- 5 2910402 10/59 Fairchfld 167:30

cidal amount of a compound of claim 1.

18. The method of controlling insects which comprises FOREIGN PATENTS contacting the insects with a toxic amount of a compound 814,152 9/51 yf l i 3, 10 667,591 3/52 Great Britain.

19. The method of protection of plants against insect attack which comprises applying to the plant an insecti- JULIAN LEVITT Primary Examm'er cidal amount of a compound of claim 3 MORRIS O. WOLK, IRVING MARCUS, Examiners. 

1. A PHOSPHONOTHIOATE OF THE FORMULA
 16. A METHOD OF CONTROLLING INSECTS WHICH COMPRISES CONTACTING THE INSECTS WITH A TOXIC AMOUNT OF A COMPOUND OF CLAIM
 1. 